Solvents such as diesel fuel have long been used to clean and degrease substrates. For example, diesel fuel is often used to remove products such as crude oil and asphalt from substrates such as equipment used for the manufacture and processing of asphalt materials. Although diesel fuel works relatively well at removing the oil-based products, diesel fuel is not considered environmentally benign and its use as an asphalt cleaner is banned in some countries.
Alternative, relatively environmentally benign solvents, such as d-limonene, have been developed to replace diesel fuel as a solvent. Unfortunately, several of these alternative solvents are generally not as efficient as diesel fuel at cleaning and degreasing, they often include volatile organic compounds, and/or they have an intolerable smell. In addition, several alternative solvent compounds have relatively low flash points, making them generally unsafe to handle. Accordingly, improved compounds and methods for cleaning and degreasing are desired.
In addition, the demand for cleaning and degreasing compounds in various cleaning and manufacturing processes is substantial and generally increasing. Thus, there is also a demand for methods and systems for recycling cleaning and degreasing compositions, to thereby reduce solvent consumption.